It was a full-fledged commune before the fusion of the Belgian municipalities in 1977.
The procession of Laetare celebrates the carnival in collaboration with the neighbouring village of Tiège. Since 1660, the flowering chariots of the two towns have been competing with each other and competing in beauty. The "White Dominoes" from Sart and "Black Dominoes" from Tiège animate the streets of the two villages and take the girls out of their house to dance.
Since 1976, Sart has been organising the Old Trades Festival. It takes place, in principle, every four years. The 11th edition took place in August 2013. Some 200 artisans and 500 actors animated the village.
- Sart-lez-Spa Terre d'accueil et de traditions